1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How to find parents' genotypes from progeny phenotype frequencies?

  1. Sep 15, 2011 #1
    Question: 8 phenotypes were observed as a result of a trihybrid cross. The frequencies of the phenotypes are

    a+ b+ c- = 570
    a- b- c+ = 545
    a+ b- c+ = 17
    a- b+ c- = 20
    a+ b- c- = 140
    a- b+ c+ = 128
    a+ b+ c+ = 65
    a- b- c- = 61

    No other information is given. It is not even specified if it is a testcross. How to know if the genes were linked? Also, what are the possible genotypes of the parents?

    My attempt - The phenotypes with the two largest frequencies represent parental classes. Thus a+ b+ c- and a- b- c+ are parental recombinant phenotypes.
    The phenotypes a+ b- c+ and a- b+ c- are double recombinant phenotypes as these have the smallest frequencies. The other 4 are single recombinant phenotypes.
    But I do not know how to proceed from here.

    Suppose I calculate the % of all the recombinant (single and double) phenotypes and find it to be less than 50%, can I conclude that the genes were linked?
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted
Similar Discussions: How to find parents' genotypes from progeny phenotype frequencies?
  1. Find frequency (Replies: 22)

Loading...